Apparatus for producing ice



Nov. 23, 1937. H. TIETZ APPARATUS FOR PRODUCING ICE 2 Sheets-Sheet lFiled Dec. 14, 1934 Nov. 23, 1937. H. TIETZ APPARATUS FOR PRODUCING ICEFiled Dec. 14, 1934 2 Sheets-Sheet 2 ATES ' a oaisi snares rca nucmo rcsTietx, Leverlsusen-Wiesdorf, Germany, a-

signor H. G. Farbenindustrie Aktiengcscll-' achait,

nirfort-on-the-Main, Geny airma December 14. 1934, Serial No. 751,544 vThe present invention relates to a process and apparatus for producingice by partial evaporationoi water in vacuo.

It is known that water is partially converted 5 into ice when subjectingit to a vacuum without supplying heat. Part of the water evaporates andwithdraws heat from the remaining part of v the water so that it freezesto ice. Various apparatus have been constructed for producing ice inaccordance with this process. Up to the present time, however, it hasnot been possible to obtain ice by this process in a continuous mannerof working because the water introduced into the vacuum chamber freezesto one ice bar which can only with the greatest difliculty be taken outof the vacuum chamberand only while interrupting the process.

In accordance with the present invention these dimculties are entirelyovercome, and a continuous production of ice is made possible bycontinuously withdrawing the ice formed in the vacuum chamber by meansof an extruding press in which the ice bar formed serves as sealingmedium for maintaining the vacuum. For this purpose a guide for the icebar is provided and this guide is formed with a slight conicity so thatthe ice bar is pressed against all parts of the guide. Among the variousextruding presses the worm extruding press has proved especiallysuitable since this press comprises the most simple mechanism and isbest to be sealed against the high vacuum. Inorder to prevent heatradiation from the outside it is advisable to .arrange the press in thevacuum chamber itself.

If the compression part of the press is to be cooled this part of theapparatus is sprayed with water. Because of the vacuum partialevaporation of the water and strong undercooling or freezing of theremainder will take place at this part.

The press is thereby cooled without a special cooling chamber beingnecessary.

For enabling a continuous working of the ice producing apparatus it hasproved advantageous to introduce the water into the apparatus in such amanner that it reaches the bottom of the apparatus in theform of ice.The introduction of the water in such a manner that it reaches thebottom of the apparatus in the form of ice can be achieved in variousways. Thus it is possible to spray'the water against-the walls of thevacuum chamber and to scrape oil the ice formed from the walls by asuitable device, or toheat the walls so that the ice falls on to thebottom from where it is withdrawn by a withdrawing device.

of the water introduced in such a manner that that the jet is givenample time to completely to (in. 62-107) the ice is obtained in the formof snow it is necessary to heat the walls of this'nozzle, for the nozzlewould be clogged by ice if the walls of the nozzle would reach atemperature below zero. This heating of thenozzle may be attained invarious ways, for instance, electrically, but since only slight heatingis required it will be suflicient to heat the walls of the nomle bymeans the water is caused to flow through the hollow walls of the nozzlebefore it enters the vacuum chamber. Thereby also pre-cooling oi thewater is attained.

In accordance with a preferred feature of the new process the water isintroduced into the vacuum chamber in one straight jet, which jet isexposed to vacuum before it touches the walls or bottom of the vacuumchamber for so long freeze under the influence of the withdrawing ofheat from its surface by partial evaporation. This can be efl'ected insuch a manner that the jet is sprayed in from the bottom to the top sothat the time during which the jet is exposed to the vacuum is prolongedby the previous rising time and on the whole amounts to twice the timethe drop requires for falling down. Further practice has shown that thejet at its turning point dissolves in single drops so that thereby thecooling and evaporating surface is essentially enlarged, on the onehand, and the form of the drops remains so large that the frozen producttakes the form of hail-stones rather than snow, on the other hand, whichhail-stones cannot be carried over, readily by the steam drawing ofl.

A still more preferred way to expose the water to the high vacuum aslong as possible without touching the walls of the vacuum chamberconsists in extending the water in a thin layer over moving surfaceswhereon it freezes, and then taking it of! in the form of ice. Thisslowly moving surface may be for instance a drum. Particularly suitableas moving surface has proved a conveyorbelt from metal, leather, orstill'better, rubber. when causing water to trickle oversuch a belt atthe one end and fixing the'velocity so that the water is frozen when thedirection of the drum or endless band is changed it has been ill foundthat the ice at the turning point separates from the band and movesforward as a fiat,-thin ice bar without any special mechanical meansbeing necessary. The band may be used horizontally, vertically as wellas in any desired oblique direction. In order to prevent water fromfreezingon the walls of the vacuum chamber caused by splashing from theband it is advisable to combine three or more bands to one closed shaftso that splashes cannot reach the outside of the shaft.

The invention is further illustrated by the accompanying drawings.

In Fig. 1 the numeral 3 indicates a worm extruding press. The wormextruding 'press 3 is arranged in the vacuum chamber l. Above the press3 there is a funnel 4. In order to prevent the ice from falling betweenthe funnel 4 and the wall of the vacuum chamber i, the wall is providedwith a flange overlapping the edge of funnel 4. For cooling thecompression part of the press a water-injector 6 is provided. The waterwhich is sprayed upon the compression part in only small quantitiesfreezes under the influence of the vacuum but is continuouslytransformed into water by the compression heat generated in the pressuntil it has completely evaporated under the influence of the vacuum.

Figures 2 and 3 represent two different devices for obtaining the ice invacuum. In these devices the water is sprayed through a nozzle I on tothe walls of the vacuum chamber. In Figure 2 the ice frozen to the wallsis scraped off by scrapers 8 which are fastened on a shaft 9, thus theice falls into the discharging device. In Figure 3 the walls of thevacuum chamber I are conically shaped and provided with a heating jacketiii. The water sprayed in first freezes at the walls, since thewithdrawal of the heat by partial evaporation in an evacuated chamberproceeds more rapidly than the heat can flow from the heating jacketwhich is cooled by the water that is sprayed in. With increasingthickness of the ice layer the passage of the heat becomes more and moredifficult and by and by the flow of the heat from the heating jacketbecomes greater than the flow of the heat through the ice. Therefore.theice will melt at the wall. the crust will break off from the wall andfall downwards into the discharging device.

Figure 4 illustrates an introduction device for the water wherein thewater expands in the noz- 71c ii, constructedv in the form of aLaval-nozzle. In this nozzle the water is transformed into snow whichfalls into the discharging device. In order to prevent clogging of thenozzle by the formation of ice the nozzle is heated. Heating preferablytakes place by means of the introduced water flowing through awater-jacket surrounding the nozzle. The water enters the waterjacket ofthe nozzle at i2 and at l3 it enters the nozzle and passes into thevacuum chamber.

Figures 5 to 9 illustrate how the ice is produced while avoiding acontact of the water sprayed in with the wall of the vacuum chamber.

For this purpose in Fig. 5 the water is sprayed into the vacuum chamberby the nozzle 1 from below to the top. The rising jet is distributed insingle drops which freeze under the influence of the vacuum tohail-stones which fall into the worm extruding press working asdischarging device.

In Figures 6 to 9 the water introduced through nozzles I is extendedupon moving surfaces in thin layers. In Fig. 6 the moving surfaces are apair of drums N moving in opposite directions from which drums the iceis taken off by the scrapers It. It then falls into the funnel l and theworm extruding press I.

In Figures '1 to 9 the moving surfaces are one or more conveyor beltsIt. In Figure 7 the conveyor belt is vertically arranged, in Figure 8 itis arranged horizontally and in Figure 9 an arrangement of threeconveyor belts IS in a closed shaft is shown in cross section.

At the upper part of the shaft in the center there is arranged the'waterintroducing nozzle 1 which distributes the water upon the three.conveyor belts. By the closed shaft any splashing of the water on to thewalls of the vacuum chamber i is avoided as any such water would freezeand thereby cause clogging of the vacuum chamber. It is not necessary toscrape off the ice from the conveyor belts, since the ice fallstherefrom at the turning point. In Figures 8 and 9 a worm extrudingpress is likewise illustrated as the discharging device.

I claim:-

1. In an apparatus for'producing ice by partial evaporation of water inan evacuated chamber, the arrangement of an extruding press. whosecross-sectional dimension diminishes toward the outlet, for withdrawingthe ice formed from the vacuum chamber and simultaneously compressingthe same into a solid to seal said outlet while sustaining the vacuum inthe chamber.

2. In an apparatus for producing ice by partial evaporation of water inan evacuated chamher. the arrangement of a moving device upon thesurface of which the water is exposed to the vacuum until it is frozenand a device for withdrawing the ice formed from the vacuum chamberwhile sustaining the vacuum.

3. In an apparatus for producing ice by partial evaporation of water inan evacuated chamber, the arrangement of a. conveyor belt upon which thewater is exposed to the vacuum until it is frozen and a device forwithdrawing the ice formed from the vacuum chamber while sustaining thevacuum.

4. In an apparatus for producing ice by partial evaporation of water inan evacuated chamber, the arrangement of a conveyor belt of rubber uponwhich the water is exposed to the vacuum until it is frozen and a devicefor withdraw-' ing the ice formed from the vacuum chamber whilesustaining the vacuum.

5. In an apparatus for producing ice by partial evaporation of water inan evacuated chamber, the arrangement of a moving device upon thesurface of which the water is exposed to the vacuum until itis frozenand an extruding press for withdrawing the ice formed from the vacuumchamber while sustaining the vacuum.

6. In an apparatus for producing ice by partial evaporation of water inan evacuated chamber, the arrangement of a conveyor belt upon which thewater is exposed to the vacuum until it is frozen and an extruding pressfor withdrawing the ice formed from the vacuum chamber while sustainingthe vacuum.

'7. In an apparatus for producing ice bypartial evaporation of water inan evacuated chamber, the arrangement of a conveyor belt of rubber uponwhich the water is exposed to the vacuum until it is frozen and anextruding press for withdrawing the ice formed from the vacuum chamberwhile sustaining the vacuum.

8. In an apparatus for producing ice by partial evaporation of water inan evacuated chamber, the arrangement of a moving device upon thesurface of which the water is exposed to the vacuum until it is frozenand a worm extruding press for withdrawing the ice formed from thevacuum chamber while sustaining the vacuum.

9. In an apparatus for producing ice by partial evaporation of water inan evacuated chamber, the arrangement of a conveyor belt upon which thewater is exposed to the vacuum until it is frozen and a. worm extrudingpress for withdrawing the ice formed from the vacuum chamber whilesustaining the vacuum.

10. In an apparatus for producing ice by partial evaporation of water inan evacuated chamber, the arrangement of a conveyor belt of rubber uponwhich the water is exposed to the vacuum until it is frozen and a wormextruding press for withdrawing the ice formed from the vacuum chamberwhile sustaining the vacuum.

HANS 111312.

